Brain Machine Interface Control of an Robotic Exoskeleton in Training Upper Extremity Functions in Stroke

Not Applicable

Completed

Conditions: Hemiparesis
Stroke

Interventions: Device: MAHI EXO-II exoskeleton augmented with BMI system

Registration Number: NCT01948739

Lead Sponsor: The University of Texas Health Science Center, Houston

Brief Summary: The purpose of this study is:

1. To augment the MAHI Exo-II, a physical human exoskeleton, with a non-invasive brain machine interface (BMI) to actively include patient in the control loop and thereby making the therapy 'active'.

2. To determine appropriate robotic (kinematic data acquired through sensors on robotic device ) and electrophysiological ( electroencephalography- EEG based) measures of arm motor impairment and recovery after stroke.

3. To demonstrate that the BMI controlled MAHI Exo-II robotic arm training is feasible and effective in improving arm motor functions in sub-acute and chronic stroke population.

Detailed Description: This study aims to provide an adjunct to accelerate neurorehabilitation for stroke patients. The MAHI EXO-II, a physical human-robot interface, will be combined with a non-invasive brain-machine interface (BMI) to actively include the patient in the training of upper extremity motor functions.

Recruitment & Eligibility

Status: COMPLETED

Sex: All

Target Recruitment: 18

Inclusion Criteria

Diagnosis of unilateral cortical and subcortical stroke confirmed by brain CT or MRI scan;
Subacute or chronic stroke; interval of at least 3month and interval of at least 6 months from stroke to time of enrollment, respectively;
No previous clinically defined stroke;
Age between 18-75 years;
Upper-extremity hemiparesis associated with stroke (manual muscle testing score of at least 2, but no more than 4/5 in the elbow and wrist flexors);
No joint contracture or severe spasticity in the affected upper extremity: i.e., significant increase in muscle tone against passive ROM is no more than ½ of full range for given joint e.g., elbow, wrist and forearm movements.
Sitting balance sufficient to participate with robotic activities;
No neglect that would preclude participation in the therapy protocol;
Upper limb proprioception present ( as tested by joint position sense of wrist);
No history of neurolytic procedure to the affected limb in the past four months and no planned alteration in upper-extremity therapy or medication for muscle tone during the course of the study;
No medical or surgical condition that will preclude participation in an occupational therapy program, that includes among others, strengthening, motor control and functional re-training of the upper limbs;
No contraindication to MRI;
No condition (e.g., severe arthritis, central pain) that would interfere with valid administration of the motor function tests;
English-language comprehension and cognitive ability sufficient to give informed consent and to cooperate with the intervention.-

Exclusion Criteria

Orthopedic limitations of either upper extremity that would affect performance on the study;
Untreated depression that may affect motivation to participate in the study;
Subjects who cannot provide self-transportation to the study location.

Inclusion and Exclusion Criteria for Health Subjects:

Inclusion criteria:

able to understand and sign the consent form
age 18-65

Exclusion criteria: - Previous history of or MRI findings consistent with brain tumors, strokes, trauma or arterial venous malformations - Contraindication to MRI - Pregnancy

Study & Design

Study Type: INTERVENTIONAL

Study Design: SINGLE_GROUP

Arm && Interventions

Group	Intervention	Description
BMI control of MAHI Exo-II	MAHI EXO-II exoskeleton augmented with BMI system	MAHI EXO-II exoskeleton augmented with BMI system will be used to actively include the patient in the control loop, thereby making the therapy 'active' and engaging patients with various impairment severity in rehabilitation tasks. Patients will receive longitudinal training with the BMI-robotic interface for 3-4 sessions per week, over a period of 3 months.

Primary Outcome Measures

Name	Time	Method
Movement Quality as Assessed by Exoskeleton Kinematics - Time to First Peak	Baseline, immediately after end of treatment (within a week)	Time to 1st Peak is a metric related to the shape of the velocity profile, and is reported as \[(time to first peak) divided by (total movement duration)\]. This value is usually less than the ideal value of 0.5, or 50%, of the total movement duration when a movement has more than one peak. The closer the value is to the ideal value of 0.5, the more well-balanced are the movements.
Neural Activity (Cortical Dynamics) Measured by Electroencephalography (EEG) Movement-related Cortical Potential (MRCP) Amplitude	Baseline, immediately after end of treatment (within a week)	EEG activity in the low-frequency delta band will be assessed. Scalp EEG electrodes will be located over the motor cortex, specifically, central (Cz, C1- C4), fronto- central (FCz, FC1 - FC4) and centro-parietal electrodes (CPz, CP1 - CP4). Further, to account for left hand vs. right hand impairment, the electrode locations will be flipped for individuals with right hand impairment. Increased MRCP amplitude indicates increased activation of the ipsi-lesional hemisphere or inhibition of competing contra-lesional hemisphere, following motor relearning.
Cortical Dynamics Measured by Electroencephalography (EEG) Movement-related Cortical Potential (MRCP) Latency	Baseline, immediately after end of treatment (within a week)	EEG activity in the low-frequency delta band will be assessed. Scalp EEG electrodes will be located over the motor cortex, specifically, central (Cz, C1- C4), fronto- central (FCz, FC1 - FC4) and centro-parietal electrodes (CPz, CP1 - CP4). Further, to account for left hand vs. right hand impairment, the electrode locations will be flipped for individuals with right hand impairment. MRCP latency is the duration of MRCP prior to movement onset, and is defined as time difference starting from 50% of peak amplitude until the time of movement onset. Increased MRCP latency indicates increased activation of the ipsi-lesional hemisphere or inhibition of competing contra-lesional hemisphere, following motor relearning.
Movement Quality as Assessed by Exoskeleton Kinematics - Average Speed	Baseline, immediately after end of treatment (within a week)	A higher value indicates better movement quality.
Movement Quality as Assessed by Exoskeleton Kinematics - Number of Peaks	Baseline, immediately after end of treatment (within a week)	Number of peaks is a metric related to the shape of the velocity profile. A higher number of peaks implies jerkier movement. A lower number of peaks indicates better movement quality (that is, movements are less jerky).
Change From Baseline in Fugl-Meyer Arm (FMA) Motor Score	Baseline, immediately after end of treatment (within a week), 2 weeks after end of treatment, 12 weeks after end of treatment	FMA is a stroke-specific, performance based impairment index. It quantitatively measures impairment based on Twitchell and Brunnstrom's concept of sequential stages of motor return in hemiplegic stroke patients. It uses an ordinal scale for scoring of 33 items for the upper limb component of the F-M scale (0:can not perform; 1:can perform partially; 2:can perform fully). Total range is 0-66, 0 being poor and 66 normal.
Movement Quality as Assessed by Exoskeleton Kinematics - Spectral Arc Length	Baseline, immediately after end of treatment (within a week)	Spectral Arc Length is a frequency-domain measure that increases in value as movements become less jerky. A higher value indicates better movement quality (that is, movements are less jerky).

Secondary Outcome Measures

Name	Time	Method
Score on Action Research Arm Test (ARAT)	Baseline, immediately after end of treatment (within a week), 2 weeks after end of treatment, 12 weeks after end of treatment	The ARAT is used to assess subject's ability to manipulate-lift-release objects horizontally and vertically, which differs in size, weight and shape. The test consists of 19 items divided into 4 sub-tests (grasp, grip, pinch, gross arm movement) and each item is rated on a 4-point scale. The possible total score ranges between 0-57. Higher scores indicate better performance.
Score on Jebsen-Taylor Hand Function Test (JTHFT)	Baseline, immediately after end of treatment (within a week), 2 weeks after end of treatment, 12 weeks after end of treatment	The JTHFT is a motor performance test and assesses the time needed to perform 7 everyday activities (for example, flipping cards and feeding). Score is reported as items completed per second.
Grip Strength	Baseline, immediately after end of treatment (within a week), 2 weeks after end of treatment, 12 weeks after end of treatment	A grip dynamometer will be used to measure maximum gross grasp force.
Pinch Strength	Baseline, immediately after end of treatment (within a week), 2 weeks after end of treatment, 12 weeks after end of treatment	A pinch gauge will be used to measure maximum pinch force.